Substrate positioning apparatus and exposure apparatus

ABSTRACT

A substrate positioning apparatus and an exposure apparatus includes a rotary circular eccentric cam mechanism as an X direction moving mechanism, in contact with one end of a support body holding a substrate, and rotary circular eccentric cam mechanisms as first and second Y direction moving mechanisms, offset in the X direction with each other, to be in contact with another side of the support body. As a result, a substrate positioning apparatus and an exposure apparatus having simple and inexpensive structure that provides satisfactory accuracy and reliability can be provided.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a substrate positioningapparatus and an exposure apparatus. More specifically, the presentinvention relates to a substrate positioning apparatus and an exposureapparatus that have a simple and inexpensive structure performingpositioning of a printed circuit board, a substrate for a flat display,a semiconductor substrate, a glass substrate or the like (hereinaftersimply referred to as a substrate) or a relative positioning between aphotomask and a substrate, with sufficient accuracy and reliability.

[0003] 2. Description of the Background Art

[0004] Conventionally, a substrate positioning apparatus is providedwith a moving apparatus for moving a substrate supporting bodysupporting a substrate in X, Y and θ, directions. The moving apparatusis arranged such that moving apparatuses for X, Y and θ, respectively,are stacked, or two moving apparatuses for Y direction are positioned onone side of a rectangle of the substrate supporting body with a spacebetween each other, and an X direction moving apparatus is positioned onan adjacent one side, and the X direction moving apparatus and two Ydirection moving apparatuses are differentially moved, so that thesubstrate is moved in the X, Y and θ directions.

[0005] Referring to FIG. 13, a structure of a moving apparatus employinga conventional positioning method using a motor and a ball screw, usedfor the substrate positioning apparatus will be described. In the movingapparatus, a method is used in which the substrate is moved in the X, Yand θ directions, so that the substrate is positioned.

[0006] A substrate 2 is held by a support body 30. On two sides (A, B)of support body 30, rotating bodies 8 are provided. In contact with therotating bodies 8, an X direction moving apparatus 200, a first Ydirection moving apparatus 210 and a second Y direction moving apparatus220, each including a ball screw 6 and motor 7, are provided for movingsupport body 30.

[0007] On two sides (C, D) opposing to the aforementioned two sides (A,B) of support body 30, springs 9 are provided, one on the side C and twoon the side D, so that support body 30 is pressed against X directionmoving apparatus 200, first Y direction moving apparatus 210 and thesecond Y direction moving apparatus 220.

[0008] In an exposure apparatus, it is very important to align aphotomask and a substrate with high accuracy, before transferring thepattern drawn on the photomask to the substrate by irradiating thesubstrate with light through the photomask. In the alignment,conventionally, a method has been adapted in which the photomask and thesubstrate are moved in X, Y and θ directions relative to each other,with the photomask and the substrates overlapped in contact with eachother or at a close distance with each other. Here, θ directionrepresents a direction of rotation in the same plane as the X and Ydirections.

[0009] The method of moving in the X, Y and θ directions is realized,similar to the substrate positioning apparatus described above, bystacking apparatuses for moving in the X, Y and θ directions,respectively, or by providing two Y direction moving apparatuses spacedapart from each other along one side of a rectangular holding means(means for holding the photomask or the substrate) and by providing oneX direction moving apparatus along another, neighboring side. In thelatter method, the position in the X direction is adjusted by the Xdirection moving apparatus, the position in the Y direction is adjustedby the Y direction moving apparatus, and the position in the θ directionis adjusted by differentially moving the two Y direction movingapparatuses.

[0010] Referring to FIG. 14, the structure of the moving apparatusemploying the conventional positioning method using motors and ballscrews will be described. In the moving apparatus, alignment is attainedby moving the photomask in the X, Y and θ directions with respect to afixed substrate.

[0011] A photomask 1 is held by a support body 30. On two sides (A, B)of support body 30, rotating bodies 8 are provided. Further, an Xdirection moving apparatus 200, a first Y direction moving apparatus 210and a second Y direction moving apparatus 220, each including a ballscrew 6, a motor 7 and the like, in contact with the rotating body 8 formoving the support body 30 are provided.

[0012] Further, on two sides (C, D) opposing to the two sides (A, B) ofsupport body 30, springs 9 are provided, one on the side C and two onthe side D, so that support body 30 is pressed to X direction movingapparatus 200 and the first and second Y direction moving apparatuses210 and 220.

[0013] On photomask 1 and substrate 2, there are photomask alignmentmark 4 and substrate alignment mark 5, provided at correspondingpositions. With the photomask 1 and substrate 2 overlapped, a CCD camera(not shown) reads the alignment marks 4 and 5 of the photomask 1 andsubstrate 2, and based on the data of the amount of positionaldeviation, the X direction moving apparatus 200 and the first and secondY direction moving apparatuses 210 and 220 are driven so that photomask1 is moved in the X, Y and θ directions and photomask 1 and substrate 2are aligned.

[0014] The structure of the X direction moving apparatus 200 and thefirst and second Y direction moving apparatuses 210 and 220 that areused in the substrate positioning apparatus and the exposure apparatusabove will be described in detail, with reference to FIG. 15. Eachmoving apparatus includes a motor 7, a motor shaft 7 a, a ball screw 6,a coupling 310 coupling motor shaft 7 a with ball screw 6, a thrustbearing 300 receiving the thrust of ball screw 6, a female screw 290 tobe engaged with ball screw 6, an end fitting 230, a linear bearing 220for linearly guiding the end fitting 230, and a frame 320 supportingthese members.

[0015] Provision on the two Y direction moving apparatuses and one Xdirection moving apparatus on another adjacent side in the abovedescribed substrate positioning apparatus and the exposure apparatus isadvantageous in that the structure is relatively simple and can be madecompact. The substrate positioning apparatus and the exposure apparatusas a whole, however, become expensive, as expensive ball screws 6 andthrust bearings 300 receiving the thrust of ball screws 6 are requiredin addition to linear bearings 220 for linear movement, the number ofcomponents is large, and assembly with the axial centers of variousparts aligned is difficult.

SUMMARY OF THE INVENTION

[0016] The present invention was made to solve the above describedproblems, and a first object is to provide a substrate positioningapparatus having a simple and inexpensive structure that performssubstrate positioning with satisfactory accuracy and reliability.

[0017] A second object is to provide a substrate positioning apparatushaving a simple and inexpensive structure performing relativepositioning between a photomask and a substrate with satisfactoryaccuracy and reliability.

[0018] The present invention provides a substrate positioning apparatushaving a base plate, holding means provided on the base plate andholding a substrate movable in X, Y and θ directions including the planeof the substrate, for detecting positions of a plurality of sides of thesubstrate or positions of positioning marks by a position detectionsensor, calculating an offset from a predetermined substrate position,moving the holding means in the X, Y and θ directions based on theresult of calculation so that the substrate is positioned to eliminatethe offset, including an X direction moving mechanism for moving theholding means in the X direction, a first Y direction moving mechanismfor moving the holding means in the Y direction, and a second Ydirection moving mechanism positioned offset in the X direction from thefirst Y direction moving mechanism, for moving the holding means in theY direction, wherein the X direction moving mechanism and the first andsecond Y direction moving mechanisms are implemented by rotating cammechanisms that are in contact with the holding means.

[0019] By this structure, the X direction moving mechanism and the firstand second Y direction moving mechanisms are implemented by usingrotating cam mechanisms, and therefore, the moving mechanisms can besimplified, and the cost necessary for each moving apparatus can bereduced. By accurately controlling the rotating angle of the rotatingcam, the amount of movement of the holding apparatus can be controlledaccurately, and hence accuracy of the moving distance and thereliability can be improved.

[0020] In a preferred embodiment of the invention, the rotating cammechanism includes an eccentric rotary member consisting of a diskeccentrically attached on a rotary shaft, or a cylindrical, circulareccentric cam, and a rolling bearing fit in an outer periphery of theeccentric rotary member, with the outer periphery of the rolling bearingbeing in contact with the holding means.

[0021] More preferably, the rotary shaft includes reading means forreading the angle of rotation of the eccentric rotary member.

[0022] In a more preferred embodiment of the invention, based on theamount of positional deviation of the substrate read by the positiondetection sensor, necessary angle of rotation of each of the circulareccentric cam to eliminate the positional deviation of the substrate iscalculated by a processor, and each circular eccentric cam is rotated inaccordance with the data.

[0023] In a more preferred embodiment, a fixing mark positioned outerthan the sides of the substrate is provided on the base plate, distancebetween the plurality of sides of the substrate or the positioning markand the fixing mark is read by the position detection sensor, and thesubstrate is positioned such that the distance between the plurality ofsides of the substrate or the positioning mark and the fixing markattains to a predetermined value, based on the read data.

[0024] In a more preferred embodiment, as each eccentric rotary member,a structure is adapted in which the disk-shaped or the cylindricalcircular eccentric cam is directly attached on an output shaft of amotor of which angle of rotation is controllable.

[0025] The present invention provides an exposure apparatus in which aphotomask and a substrate are overlapped close to each other or incontact with each other, for transferring a pattern drawn on thephotomasks to the substrate by irradiating the substrate with lightthrough the photomask, and the apparatus has the following structure.

[0026] More specifically, the exposure apparatus includes an alignmentapparatus for aligning the photomask and the substrate, wherein thephotomask and the substrate are provided with a plurality of alignmentmarks at corresponding positions, respectively, the alignment marks onthe photomask and the substrate are read by a CCD camera with thephotomask and the substrate being overlapped, and the photomask and thesubstrate are moved in X, Y and θ directions relative to each otherbased on the data read by the CCD camera, so that the photomask and thesubstrate are aligned.

[0027] The alignment apparatus has a holding apparatus holding one ofthe photomask and the substrate that moves, and movable in the directionof the plane of the photomask or the substrate; an X direction movingmechanism for moving the holding apparatus in the X direction; a first Ydirection moving mechanism for moving the holding apparatus in the Ydirection; and a second Y direction moving mechanism for moving theholding apparatus in the Y direction, positioned offset in the Xdirection from the first Y direction moving mechanism. Further, the Xdirection moving mechanism and the first and second Y direction movingmechanisms are implemented by rotating cam mechanisms that are incontact with the holding apparatus.

[0028] By this structure, the X direction moving mechanism and the firstand second Y direction moving mechanisms are implemented by usingrotating cam mechanisms, and therefore the moving mechanisms can besimplified and the cost necessary for each moving apparatus can bereduced. By accurately controlling the rotating angle of the rotatingcam, the amount of movement of the holding apparatus can be controlledaccurately, and hence accuracy of the moving distance and thereliability can be improved.

[0029] In a preferred embodiment of the present invention, the rotatingcam mechanism includes a disk eccentrically attached on a rotary shaft,or an eccentrical rotary member consisting of a circular eccentric cam,and a rolling baring fit in an outer periphery of the eccentric rotarymember, with the outer periphery of the rolling bearing being in contactwith the holding apparatus.

[0030] More preferably, the rotary shaft further includes a readingapparatus for reading the angle of rotation of the eccentric rotarymember.

[0031] In a more preferred embodiment, there is further provided animage processing apparatus for recognizing the amount of positionaldeviation between the photomask and the substrate read by the CCDcamera, calculating means calculating the amount of positional deviationbetween the photomask and the substrate based on the information fromthe image processing apparatus, and an output apparatus applying anecessary angle of rotation of each eccentric rotary member, to the Xdirection moving mechanism and the first and second Y direction movingmechanisms so as to eliminate the positional deviation between thephotomask and the substrate.

[0032] In a more preferred embodiment, as each eccentric rotary member,a structure is adapted in which the disk or the cylindrical, circulareccentric cam is directly attached on an output shaft of a motor ofwhich angle of rotation is controllable.

[0033] The foregoing and other objects, features, aspects and advantagesof the present invention will become more apparent from the followingdetailed description of the present invention when taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0034]FIG. 1 shows a principle of the method of positioning using arotary circular eccentric cam of the substrate positioning apparatus inaccordance with a first embodiment.

[0035]FIG. 2A is a schematic illustration representing the relationbetween “angle of rotation θ of circular eccentric cam 11” and “amountof movement S of support body 3” and FIG. 2B is a graph representing therelation between “angle of rotation θ of circular eccentric cam 11” and“amount of movement S of support body 3.”

[0036]FIG. 3 is a plan view (viewed from the line III-III of FIG. 4)showing the structure of the substrate positioning apparatus inaccordance with the first embodiment.

[0037]FIG. 4 is a cross sectional view taken along the line IV-IV ofFIG. 3.

[0038]FIG. 5 is a perspective view representing positional relationbetween each of upper base plate 24A, fixing marks 6, 7 and 8 and asubstrate base plate 30C of the substrate positioning apparatus inaccordance with the first embodiment.

[0039]FIG. 6 is a perspective view representing positional relationbetween each of upper base plate 24A, a lower base plate 24B, a firstsupport body 30A, a second support body 30B and substrate base plate 30Cof the substrate positioning apparatus in accordance with the firstembodiment, except for fixing marks 6, 7 and 8.

[0040]FIG. 7 shows detailed structure of the supporting portion ofsupport body 30 of the substrate positioning apparatus in accordancewith the first embodiment.

[0041]FIG. 8 shows positioning of substrate 2 and support body 30 by thesubstrate positioning apparatus in accordance with the first embodiment.

[0042]FIG. 9 shows a principle of the alignment method using the rotarycircular eccentric cam of the exposure apparatus in accordance with asecond embodiment.

[0043]FIG. 10 is a block diagram of a processor in the exposureapparatus in accordance with the second embodiment.

[0044]FIG. 11 is a plan view (viewed from the direction of the arrowXI-XI of FIG. 12) showing the structure of the exposure apparatus inaccordance with the second embodiment.

[0045]FIG. 12 is a cross sectional view taken along the line XII-XII ofFIG. 11.

[0046]FIG. 13 shows a principle of the positioning method ofconventional substrate positioning apparatus.

[0047]FIG. 14 shows a principle of the method of alignment of theconventional exposure apparatus.

[0048]FIG. 15 shows a structure of the conventional moving apparatusused in the substrate positioning apparatus and the exposure apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0049] Embodiments of the substrate positioning apparatus and theexposure apparatus to which the present invention is applied will bedescribed with reference to the figures.

[0050] (First Embodiment)

[0051] The structure of the substrate positioning apparatus inaccordance with the present embodiment will be described with referenceto FIG. 1. FIG. 1 shows the principle of positioning using the rotarycircular eccentric cam of the substrate positioning apparatus inaccordance with the present embodiment. Portion the same as orcorresponding to those of the conventional substrate positioningapparatus described with reference to FIG. 13 will be denoted by thesame reference characters, and detailed description thereof will not berepeated.

[0052] (Schematic Structure of the Substrate Positioning Apparatus)

[0053] Referring to FIG. 1, the substrate positioning apparatus inaccordance with the present embodiment is characterized by rotarycircular eccentric cam mechanisms 100, 110, and 120.

[0054] More specifically, a rotary circular eccentric cam mechanism 100is provided as the X direction moving mechanism to be in contact withone side (A) of support body 30 holding substrate 2, and a rotarycircular eccentric cam mechanism 110 as the first Y direction movingmechanism and a rotary circular eccentric cam mechanism 120 as thesecond Y direction moving mechanism are provided at positions offset inthe X direction, to be in contact with another side (B) of support body30. By this structure, it becomes possible to move the substrate in theX, Y and θ directions. Here, θ direction refers to a direction ofrotation in the same plane as the X and Y directions.

[0055] The rotary circular eccentric cam mechanism includes a rollingbearing 11 b in contact with a support body fitting 28 provided on aside of support body 30, a circular eccentric cam 11 a to which outerperipheral surface the rolling bearing 11 b is fitted, and a rotaryshaft 10 transmitting rotary driving force to the circular eccentric cam11 a.

[0056] (Relation Between the Angle of Rotation θ and the Amount ofMovement S)

[0057] Referring to FIGS. 2A and 2B, the relation between “the angle ofrotation θ of the circular eccentric cam 11” and “the amount of movementS of support body 30” will be described. Referring to FIG. 2A, assumethat a position, where a line (L1) connecting the center of the rotaryshaft 10 and the center of the circular eccentric cam 11 is parallel toone side of support body 30 with which circular eccentric cam 11 is incontact, is considered as the origin (0 point) of the angle of rotationθ. Assuming that one side of support body 30 moves parallel to the line(L1), the relation between the “angle of rotation θ of circulareccentric cam 11” and “the amount of movement S of support body 30” whenthe circular eccentric cam 11 is rotated in ± directions is as shown bythe graph of FIG. 2B. The curve of the graph can be represented by theequation S=sin θ.

[0058] (Specific Structure of the Substrate Positioning Apparatus)

[0059] Referring to FIGS. 3 and 6, more specific structure of thesubstrate positioning apparatus using the rotary circular eccentric cammechanism in accordance with the present embodiment will be described.FIG. 3 is a plan view (viewed from the line III-III of FIG. 4) showingthe structure of the substrate positioning apparatus of the presentembodiment, and FIG. 4 is a cross sectional view taken along the lineIV-IV of FIG. 3. FIG. 5 is a perspective view representing positionalrelation between each of upper base plate 24A, fixing marks 6, 7 and 8and a substrate base plate 30C, and FIG. 6 is a perspective viewrepresenting positional relation between each of upper base plate 24A, alower base plate 24B, a first support body 30A, a second support body30B and substrate base plate 30C, except for fixing marks 6, 7 and 8.

[0060] Substrate 2 is supported by vacuum suction on a substrate baseplate 30C. Substrate base plate 30C is mounted to fix on a secondsupport body 30B with a first support body 30A interposed. On one side(A) of second support body 30B, a support body fitting 28 is providedand rotary circular eccentric cam mechanism 100 as the X directionmoving mechanism is provided in contact with the support body fitting28. On another side (B) of second support body 30B, two support bodyfittings 28 are provided at positions offset in the X direction fromeach other, and rotary circular eccentric cam mechanism 110 as the firstY direction moving mechanism and rotary circular eccentric cam mechanism120 as the second Y direction moving mechanism are provided to be incontact with the support body fittings 28, respectively. Further, on twosides (C, D) opposing to the aforementioned two sides (A, B) of secondsupport body 30B, springs 9 are provided, one on the side C and two onthe side D, so that second support body 30B is pressed against Xdirection moving apparatus 100, first Y direction moving apparatus 110and second Y direction moving apparatus 120.

[0061] The rotary circular eccentric cam mechanism includes a rollingbearing 11 b, a circular eccentric cam 11 a to which outer periphery therolling bearing 11 b is fitted, a rotary shaft 10 transmitting rotarydriving force to the circular eccentric cam 11 a, and a motor forrotary-driving the rotary shaft 10. A disk shaped or cylindrical camshould preferably be used as the circular eccentric cam 11 a. Further, areading apparatus such as an encoder for reading the angle of rotationshould preferably be provided on the circular eccentric cam 11 a. Morepreferably, a motor of which angle of rotation of the output shaft iscontrollable should preferably be used as motor 32. Further, it ispossible to perform control in which angle of rotation of the rotaryshaft 10 is recognized, using a pulse motor and an apparatus fordetecting an origin (0 point) of the angle of rotation θ which is theposition where the circular eccentric cam 11 a becomes parallel to oneside of the second support body 30B which is in contact therewith.Further, a CCD camera 12 is provided on the side of substrate 2, ofsubstrate base plate 30C.

[0062] Referring to FIG. 7, detailed structure of the supporting portionof second support body 30B will be described. This is a structuresupporting second support body 30B movable in the X and Y directionswhile preventing movement in the Z direction, in which a flat plateportion 28 a of support body fitting 28 is gripped and supported by apair of bearings 26 having balls 27 held freely rotatable by a housing25. One of the bearings 26 is provided directly on upper base plate 24A,while the other bearing 26 is provided in a bracket 21 fixed on upperbase plate 24A. Upper base plate 24A is supported by a support bar 24Con lower base plate 24B.

[0063] Referring to FIG. 8, substrate 2 held on substrate base plate 30Cis positioned relative to upper base plate 24A in the following manner.Distance between fixing marks 6, 7 and 8 provided on upper base plate24A and the corresponding side or positioning mark of substrate 2 isread by CCD camera 12 as the position detection sensor, and based onread information of the offset of substrate 2, the amount of offset ofsubstrate 2 is calculated by a processor. Thereafter, based on theresult of calculation, necessary angle of rotation for each circulareccentric cam 11 a is provided from the processor, for X directionmoving mechanism 100 and the first and second Y direction movingmechanisms 110 and 120, so as to eliminate the positional deviation ofsubstrate 2. Substrate base plate 30C has a notch portion 30 k, so thatfixing marks 6, 7 and 8 provided on upper base plate 24A can be read byCCD camera 12.

[0064] (Function and Effects)

[0065] According to the substrate positioning apparatus in accordancewith the present embodiment, the X direction moving mechanism 100 andthe first and second Y direction moving mechanisms 110 and 120 can beimplemented by using rotary cam mechanisms, and hence the movingmechanism can be simplified. Further, by accurately controlling theangle of rotation of the rotary cam, the amount of movement of theholding apparatus can be managed accurately. Therefore, accuracy of themoving distance and reliability can be improved. It is possible to adoptsuch a structure that includes a belt conveyer or a roller conveyer inplace of substrate base plate 30C.

[0066] (Second Embodiment)

[0067] In the following, the structure of the exposure apparatus inaccordance with an embodiment of the present invention will be describedwith reference to FIG. 9. FIG. 9 shows a principal of the method ofpositioning using rotary circular eccentric cam of the exposureapparatus in accordance with the present embodiment. Portions similar toor corresponding to those of the conventional exposure apparatusdescribed with reference to FIG. 14 will be denoted by the samereference characters, and detailed description will not be repeated.

[0068] (Schematic Structure of the Exposure Apparatus)

[0069] Referring to FIG. 9, the moving apparatus of the exposureapparatus in accordance with the present embodiment is characterized inthat rotary circular eccentric cam mechanisms 100, 110 and 120 areprovided, partially improving the conventional moving apparatus shown inFIG. 14.

[0070] More specifically, as the X direction moving mechanism, therotary circular eccentric cam mechanism 100 is provided to be in contactwith one side (A) of support body 30 on which photomask 1 is held, andas the first Y direction moving mechanism and the second Y directionmoving mechanism, rotary circular eccentric cam mechanisms 110 and 120are provided, opposite in the X direction from each other, to be incontact with another side (B) of support body 30. The substrate 2positioned close to photomask 1 is represented by a two-dotted line inFIG. 9.

[0071] By such a structure, it becomes possible to move the photomask inthe X, Y and θ directions relative to the substrate. Here, θ directionrepresents a direction of rotation in the same plane as the X and Ydirections.

[0072] The rotary circular eccentric cam mechanism includes a rollingbearing 11 b in contact with a support body fitting 28 provided on theside of support body 30, a circular eccentric cam 11 a having therolling bearing 11 b fitted in an outer peripheral surface thereof, anda rotary shaft 10 transmitting the rotary driving force to the circulareccentric cam 11 a. Though rolling bearing 11 b is provided to reducerolling friction, support body fitting 28 may be provided sidable alongthe side of support body 3, instead of providing the rolling bearing 11b.

[0073] The relation between the angle of rotation θ and the amount ofmovement S is the same as described with reference to FIG. 2. Therefore,description thereof will not be repeated here.

[0074] (Processor)

[0075]FIG. 10 is a block diagram of the processor reading the alignmentmark 4 provided on photomask 1 and alignment mark 5 provided onsubstrate 2 by a CCD camera 12 and performing data processing thereof.More specifically, alignment mark 4 of photomask 1 and alignment mark 5of substrate 2 are irradiated by a light source 13 with the photomask 1and substrate 2 overlapped with each other, and read by CCD camera 12.

[0076] The image of the read alignment marks 4 and 5 is processed byimage processing apparatus 14, of which data is transmitted to acalculating apparatus 15, where the amount of positional deviationbetween alignment mark 4 and alignment mark 5 is calculated and theamount of movement of each of the rotary circular eccentric cammechanisms 100, 110 and 120 for canceling the amount of positionaldeviation is calculated, and transmitted to an output apparatus 16 fordriving the rotary circular eccentric cam mechanisms 100, 110 and 120.The mechanism of the calculating apparatus is applicable to thesubstrate positioning apparatus in accordance with the first embodimentdescribed above.

[0077] (More Specific Structure of the Exposure Apparatus)

[0078] More specific structure of the exposure apparatus using therotary circular eccentric cam mechanisms in accordance with the presentembodiment will be described with reference to FIGS. 11 and 12. FIG. 11is a plan view (viewed from the line XI-XI of FIG. 12) showing thestructure of the exposure apparatus in accordance with the presentembodiment, and FIG. 12 is a cross sectional view taken along the lineXII-XII of FIG. 11.

[0079] Similar to the exposure apparatus shown in FIG. 9, photomask 1 isheld by a support body 30. Substrate 2 is supported by a substrateholder 31 by vacuum suction, and the substrate holder 31 is supported bya substrate base plate 32. Substrate base plate 32 is supported on abase plate 24 by means of a guide pin 29.

[0080] On one side (A) of support body 30, support body fitting 28 isprovided, and as the X direction moving mechanism, the rotary circulareccentric cam mechanism 100 is provided to be in contact with thesupport body fitting 28. On another side (B) of support body 30, twosupport body fittings 28 are provided offset from each other in the Xdirection, and as the first and second Y direction moving mechanisms,rotary circular eccentric cam mechanisms 110 and 120 are provided to bein contact with the support body fittings 28, respectively. On two sides(C, D) opposing to the two sides (A, B) of support body 30, springs 9are provided, one on side C and two on side D, to press the support body30 in the direction of X direction moving apparatus 100 and the firstand second Y direction moving apparatuses 110 and 120.

[0081] The rotary circular eccentric cam mechanism includes a rollingbearing 11 b, a circular eccentric cam 11 a having the rolling bearing11 b fitted on an outer peripheral surface thereof, a rotary shaft 10transmitting a rotary driving force to the circular eccentric cam 11 a,and a motor 17 for driving and rotating the rotary shaft 10. A diskshaped or a cylindrical, circular eccentric cam 11 a is preferred.Preferably, a reading apparatus such as an encoder for reading the angleof rotation of circular eccentric cam 11 a is provided on the rotaryshaft 10. More preferably, a motor of which angle of rotation of anoutput axis is controllable, should be used as motor 17. Alternatively,the origin (0 point) of the angle of rotation θ, which is the positionwhere the aforementioned line and the side of support body 30 with whichthe circular eccentric cam 11 is in contact are parallel to each othermay be detected by a detecting apparatus, and a pulse motor or a servomotor that can accurately control the angle of rotation from the originto the necessary angle may be used to rotate the rotary shaft 10.

[0082] On the light source side of base plate 24, an apparatus 20 formoving a camera in X direction is provided, supporting CCD camera 12movable in the X direction, and an apparatus 19 for moving the camera inY direction is further provided, supporting the apparatus 20 movable inthe Y direction. FIG. 5 shows a guide rail 18 supporting CCD camera 12movable in the Y direction.

[0083] The detailed structure of the supporting portion of support body3 is the same as the structure shown in FIG. 5. Therefore, descriptionthereof will not be repeated.

[0084] (Function and Effects)

[0085] As described above, by the exposure apparatus in accordance withthe present embodiment, the X direction moving mechanism 100, the firstY direction moving mechanism 110 and the second Y direction movingmechanism 120 can be realized by rotating cam mechanisms, and hencemoving mechanisms can be simplified. Further, by accurately controllingthe rotating angle of the rotating cam, the amount of movement of theholding apparatus can be adjusted accurately. Therefore, accuracy in thedistance of movement and the reliability can be improved. In theprocessor shown in FIG. 10, a program for calculating the angle ofrotation θ of the rotary eccentric cam 11 a is necessary. However, asthe structure of the moving mechanisms can be simplified, the cost ofthe overall exposure apparatus can be reduced.

[0086] Further, in the above described embodiment, the support body 30supporting photomask 1 is made movable in X and Y directions whilesubstrate holder 31 supporting the substrate 2 is fixed. It is alsopossible to fix the support body 30 supporting photomask 1, whilesubstrate holder 31 supporting the substrate 2 is made movable in X andY direction. Any mechanism may be adapted, provided that photomask 1 andsubstrate 2 can be moved in X, Y and θ directions relative to eachother.

[0087] In the substrate positioning apparatus and the exposure apparatusof the present invention, as the X direction moving mechanism and thefirst and second Y direction moving mechanisms are implemented byrotating cam mechanisms, the moving mechanisms can be simplified and thecost necessary for each moving apparatus can be reduced. Further, byaccurately controlling the rotating angle of the rotating cam, theamount of movement of the holding apparatus can be adjusted accurately,and hence accuracy in positioning and the reliability can be improved.

[0088] Although the present invention has been described and illustratedin detail, it is clearly understood that the same is by way ofillustration and example only and is not to be taken by way oflimitation, the spirit and scope of the present invention being limitedonly by the terms of the appended claims.

What is claimed is:
 1. A substrate positioning apparatus, having a baseplate, holding means provided on the base plate and holding a substratemovable in X, Y and θ directions including a plane of the substrate,detecting positions of a plurality of sides of said substrate or aposition of a positioning mark by a position detection sensor,calculating an amount of deviation from a predetermined position of thesubstrate, and positioning said substrate by moving said holding meansin the X, Y and θ directions based on the result of calculation toeliminate the amount of deviation, comprising: an X direction movingmechanism moving said holding means in the X direction; a first Ydirection moving mechanism moving said holding means in the Y direction;and a second Y direction moving mechanism positioned offset in the Xdirection from said first Y direction moving mechanism, moving saidholding means in the Y direction; wherein said X direction movingmechanism, said first Y direction moving mechanism and said second Ydirection moving mechanism are implemented by rotary cam mechanisms incontact with said holding means.
 2. The substrate positioning apparatusaccording to claim 1, wherein said rotary cam mechanism includes aneccentric rotary member implemented as a disk or a cylindrical circulareccentric cam attached eccentrically on a rotary shaft, and a rollingbearing fitted in an outer periphery of said eccentric rotary member;and an outer periphery of said rolling bearing is in contact with saidholding means.
 3. The substrate positioning apparatus according to claim1, wherein said rotary shaft further includes reading means for readingangle of rotation of said eccentric rotary member.
 4. The substratepositioning apparatus according to claim 2, wherein necessary angle ofrotation each said circular eccentric cam to eliminate positionaldeviation of said substrate is calculated by a processor based on theamount of deviation of said substrate read by said position detectionsensor, and each said circular eccentric cam is rotated in accordancewith the data.
 5. The substrate positioning apparatus according to claim1, wherein a fixing mark positioned outer than a side of said substrateis provided on said base plate, a distance between the plurality ofsides of said substrate or the positioning mark and said fixing mark isread by said position detection sensor, and based on the read data, saidsubstrate is positioned so that the distance between the plurality ofsides of said substrate or the positioning mark and said fixing markattains to a predetermined value.
 6. The substrate positioning apparatusaccording to claim 2, wherein each said eccentric rotary member includessaid disk shaped or said cylindrical circular eccentric cam directlyattached to an output shaft of a motor of which angle of rotation iscontrollable.
 7. An exposure apparatus, in which a photomask and asubstrate are overlapped close to each other or in contact with eachother, a pattern drawn on said photomask being transformed to saidsubstrate by irradiating said substrate with light through saidphotomask, wherein said photomask and said substrate are provided with aplurality of alignment marks at positions corresponding to each other,for alignment of said photomask and said substrate; the alignment marksof said photomask and said substrate are read by a CCD camera with saidphotomask and said substrate overlapped with each other; said exposureapparatus comprising alignment means for aligning said photomask andsaid substrate, as said photomask and said substrate are moved in X, Yand θ directions relative to each other, based on data read by said CCDcamera, said alignment means having holding means for holding one ofsaid photomask or said substrate that moves, and movable along a planedirection of said photomask or said substrate, an X direction movingmechanism for moving said holding means in the X direction, a first Ydirection moving mechanism for moving said holding means in the Ydirection, and a second Y direction moving mechanism positioned offsetin X direction from said first Y direction moving mechanism and movingsaid holding means in the Y direction, said X direction movingmechanism, said first Y direction moving mechanism and said second Ydirection moving mechanism are each a rotating cam mechanism in contactwith said holding means.
 8. The exposure apparatus according to claim 7,wherein said rotating cam mechanism includes an eccentric rotary memberconsisting of a disk or a cylindrical circular eccentric cam attachedeccentrically on a rotary shaft, and a rolling bearing fitted in anouter periphery of said eccentric rotary member, said rolling bearinghaving an outer periphery being in contact with said holding means. 9.The exposure apparatus according to claim 7, wherein said rotary shaftfurther includes reading means for reading an angle of rotation of saideccentric rotary member.
 10. The exposure apparatus according to claim8, further comprising: image processing means for recognizing an amountof positional deviation between said photomask and said substrate readby said CCD camera; and output means for calculating the amount ofpositional deviation between said photomask and said substrate based oninformation from said image processing means, and for outputtingnecessary angle of rotation of each said eccentric rotary member to saidX direction moving mechanism, said first Y direction moving mechanismand said second Y direction moving mechanism, so as to eliminate thepositional deviation between said photomask and said substrate.
 11. Theexposure apparatus according to claim 8, wherein each said eccentricrotary member includes said disk shaped or said cylindrical circulareccentric cam attached directly on an output shaft of a motor, of whichangle of rotation is controllable.